Blue cotton sulfur dye and process of making same.



UNITED STATES PATENT ()FFICE.

HERMANN GUSSMANN, OF HGCHST-ON-THE-MAIN, GERMANY, ASSIGNOR TO THE FARBWERKE, VORMALS MEISTER, LUCIUS & BRIINING, OF SAME PLACE.

BLUE COTTON SULFUR DYE AND PROCESS OF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 657,769, dated September 1 1, 1900. Original application filed June 3, 1899, berial No. 719,292. Divided and this application filed November '7, 1899. Serial No- To fbZZ whom. it may concern.-

Be it known that I, HERMANN GUSSMANN, Ph. 1)., a citizen of the Empire of Germany, residing at I-Iochst-on-the-Main, Germany,

have invented certain new and useful Improvements in the Manufacture of a Blue Sulfnrized Dyestutf from Oxynitro or Oxy-amido Diphenylaminsulfonic Acid, of which the following is a specification.

lo I have shown in a previous application, Serial No. 719,292, filed June 3, 1899, that dioxyamidodiphenylamin of the formula obtained by heating p-oXy-p-amido-diphenylaminsulfonic acid yields when heated with sulfur and sulfids 5 of alkali metals a blue directly-dyeing dyestuff. I now have found that a yet more valuable blue dyestuff may be obtained if instead of dioxydiphenylamin oxynitro or oxyamidodiphenylaminsulfonic acid be di- 3 rectly heated with sulfur and sulfids of alkali metals. The nitro group is thus transformed into the NH group.

Example: Into a molten mixture of one hundred parts, by Weight, of sodium sulfid and thirty parts, by weight, of sulfur are introduced thirty parts, by Weight, of oxyamidodiphenylaminsulfonic acid at about 130 centigrade and heated to from 160 to 180 centigrade till an evolution of hydro- 0 gen sulfid no longer takes place and the mass (N0 specimens.)

begins to thicken. The mass is then dis solved in water, and the liquid containing the dyestuff in form of its leuco compound is oxidized by introducing a current of air. After oxidation it is filtered from the sepa- 5 rated sulfur and the dyestuff is precipitated from its aqueous solution by adding common salt. The dry dyestuff thus obtained is when pulverized a dark powder of coppery luster easily soluble in Water with a blue color. Mineral acids precipitate the dyestuif from its aqueous solution as blue flakes. In sulfuric acid the dyestutf dissolves with a bluegreen color.

Having now described my invention, what I claim is 1. The herein-described process of producing a blue cotton dyestuff, which consists in heating para-oXy-para-amido-diphenylaminsulfonic acid to from 160 to 200 centigrade with sulfur and sulfids of alkali metals and then treating the mass thus obtained in an aqueous solution with oxidizing agents, substantially as set forth.

2. As a new product, the herein-described dyestuff derived from diphenylaminsulfonic acid and sulfur, said dyestuif being when pulverized a dark powder of coppery luster, readily soluble in water with a blue color, mineral acids precipitating the dyestuff from its aqueone solutions in blue flakes, the dyestuff dissolving in sulfuric acid with a blue-green color, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name in presonce of two subscribing witnesses.

HERMANN GUSSMANN.

Witnesses:

HEINRICH HAHN, ALFRED BRIsBoIs. 

